Fatigue life prediction of a woven fabric composite subjected to biaxial cyclic loads

Abstract The purpose of this paper is to apply the Bridging micromechanics model to simulate the fatigue strength and S–N curve of a plain-woven fabric reinforced composite subjected to multiaxial cycling loads. Only the in situ constituent fiber and matrix properties, including the S–N data under the same cycling condition as that applied to the composite and the fiber volume fraction, are required. A unit cell of the woven composite is subdivided into small slices, each of which can be considered as a unidirectional (UD) composite. The load shared by each UD composite can be determined based on an assemblage scheme, as long as the overall fatigue load has been given. The Bridging model is adopted to explicitly relate the internal stresses in the constituent fiber and matrix materials with the load shared by the UD composite, and further, with the overall fatigue load on the woven composite. These stresses are then detected using the maximum normal stress criterion of isotropic materials against the constituent fatigue strengths, and the composite fatigue failure (strength) is attained (defined) when a constituent fails. A plain-woven glass fiber fabric reinforced polyester matrix composite subjected to uniaxial and biaxial static and fatigue loads has been analyzed. Agreement between the predicted and available experimental results is reasonable.